As of June 2016, the availability of the One Step Beyond series on DVD is complicated, with various

releases containing different numbers of episodes, different qualities of transfer, and even different episode titles:

One Step Beyond: The Official First Season (2009).

This is the only "official" commercial release from
Paramount TV, producers of the series. It contains
all 22 episodes of Season 1 and was created from the
original 35mm television broadcast prints. These are
the best quality episodes available. Unfortunately, no
similar release for Seasons 2 and 3 has yet occurred.

Recommended.

One Step Beyond 6 DVD Collector's Set (2015).

This is a "public domain" release of 70 of the series'
96 episodes: all 22 from Season 1 . . . 32 of 39 from
Season 2 . . . and 16 of 35 from Season 3. These are
transfers of 16mm syndication prints that vary in quality.
Nevertheless, the overall quality is fairly good and this
is the most complete set available.

Recommended.

Dozens of Titles . . . (Various Dates).

These are "public domain" collections, with varying
numbers of episodes and formats, and are generally
of lower quality. They rarely if ever offer additional
episodes that are not available in the better quality
releases.

Not recommended.

2 or 3 Titles . . . (Various Dates).

These are "bootleg" releases from various sources --
especially recordings from actual network broadcasts.
Some undoubtedly contain episodes not found on
commercial releases . . . and that's the only advantage
they offer.